Fire door



Patented Sept. 6, 1927.

UNTTED STATES i l 1,641,506 PATENT oFFlClz.I

SAMUEL P. SMURR, F CHICAGO, LLINOS, ASSGrNOR OF ONE-HALF TOIIUGO A.

HUELSE, OF CHICAGO, ILLINOIS.

FIRE- DOOR.

My invention relates to lire doors of the rolling shutter type, and has for its objects improvements in devices of that kind.

The shutter or curtainr of this type ofdevice is composed of a plurality of metal slats connected together and wound upon being secured to the upper end of the cur-v tain. As the shaft of such construction must be turned in its bearings to wind the spring, and as the barrel must turn on the shaft to .raise and lower the door or curtain, it is evident that the shaft must be round. As such supporting shaft must be drilled for the attachment of the spring. and for connections by which to turn it in winding the spring, it is evident that the shaft isk con siderably weakened. In the case of doors twelve to twenty feet wide', the great weight of the barrel and .metal slats on this Aweakened shaft bends or distorts it so as to 'cause it to be out of alignment, and this in turn' causes undue friction in the bearings and impairs the operation of the device. The.

main objectv of the present invention is to overcome the troubles and difficulties which f arise directly or indirectly fromr the use of structures such as that above indicated.

In the accompanying drawings-A Fig. 1 is a longitudinal section thru the barrel; y n

Fig. 2 is a section on line 2-2 of Fig. 1; and s Fig. 3 is an end elevation.

The brackets 11 and 12 are secured to the wall'of the building at the sides of the doorway which is to be closed by the curtain or shutter lsecured in-the ordinary way to the barrel 14. `The barrel extends thru the brackets and hasV bearings therein. These 5 t6 the 'short necks of the dumbbells, and

bearings Yare roller bearings, the rollers 15.

The conconsequently to the narrow bearing surface in the brackets 11 and 12, the bearings of the barrel may be materially out of line without affecting the operation Yof the device-` This is an advantage in erection as it does not maken'ecessary great care in bringing the bearings into` exact line. It is also of advantage in wide doors, the heavy curtains of'which cause the barrel to sag in the center. The dumbbell shape of the rollers 15 65 also provides means for applying the roller spacing strips 16. These are metal strips of a width a triiie less than the length of the neckbetween the headsof the dumbbells, and are crimped as shown in Fig. 2. One strip for each bearing lies between the kbarrel yand the necks of the rollers.

l'As a convenientv means for inserting and withdrawing the rollers7 there is provided a small opening 17 in the web of the brackets justabove the bearings therein. As the weight ison the lower part of the bearings, the roilers will not get out of themselves, but maybe readily removed by lifting them nanually one at a time and moving them axially'. Itis alsolto be observed that when thesevrollers are in position in a bearing, they are restrained from axial displacement by the heads which are onopposite sides of the bearing in the bracket.V y 1` 85" It willthus be seen' kthat the dumbbellV shape here serves three purposes. One is providing for' ordinary displacement of the barrel from'alignment without causing fric# tion,` a second is providing room for a spacery 16, and the third ris providing means for retaining the rollers from axial displacement without providing closers or keepers for that purpose; K Secured'to the outer faces of the brackets 11 and. 12 are covers 18 and 19 which are provided with hubs 20 and 21. These hubs may, and preferably do, extend into the ends of the barrel as Ashown in Fig. 1. These covers are secured to th-e brackets by bolts l22 which pass lthru slots 23. VThese covers are alike except that hub 21has a square hole tdt the square shaft y2li, yand hub 2,0 has a round hole in which lthe shaft may be turned. VOrjhub 2O may be" reducedv to a simple boss Vagainst whi h theend of the.` shaft abuts. ,'Vithin the barrel 14.- and onthe Shaft 24:4 'are' screws 25and 26 providedvwith heads 27 and 28. The screw 25 hasa round' axial 1Mo opening large enough to permit it to turn freely on the square shaft, and a head which fits the interior of the barrel 14. 1t is secured to the barrel by cap screws 29. The screw 26 has a square axial opening to fit the shaft 2li and a head of slightly less diameter than the interior of the barrel. It is secured to the shaft by means of the set screw 30.

Mounted upon screws 25 and 26 is a helical spring 31 having inturned ends 32 which project into the threads of the screws. rlhese parts are so arranged that for a right hand spring the screws have left hand threads, and for a left hand spring the screws have right hand threads. vnilliese screws are inserted in the ends of the spring by simply screwing thein in until the inturned ends come to the ends of the threads adjacent to the heads'27 and 28.

In a device of this kind in which the spring 31 must 'be wound up to support a long heavy curtain, the said spring must be given a pre-stretch (shown exaggerated in the drawings) to accoiiin'iodate the eXtra number ofturns given to the spring in the winding operationp rlChis pre-stretch is determined by a piece of tubing 33 mounted on the shaft between the screws 25 and 26.

It will be assumed that the vparts are erected shown in Fig. 1, and that the curtain 13 hangs down to cover the doorway. Theneirt step is to remove the screws 22 of cover 19, and apply a spanner to the slots 23 for the purpose of turning the shaft 24 to wind spring llilhen the spring has been wound enough to practically` balance the weight of the curtain, screws 22 are returned to place and. the cover thus secured in position.

Returning nowpt the matter before men tioned, if the weight and length of the curtain are known, a proper size and length of spring may be determined. by calculation. Also,r.there may be calculated in advance the number of turns which it will be necessary to give the spring in balancing the weight.

of the curtain intheopcration previously described. 1fn this position, with the eurtain down, the adjacentv coils of thespring should be close together but not quite touching.'V Under the tension which winds the spring, the intiirned ends 32 are close to the heads 27 and 23, and remain permanently in that position. sthe desired length of the wound spring is determined by calculation, and the length of the screws 25 and 26 are known',v it is a simple matter to determine the; proper length of thefspacing tube 33 :which will ygive the least practicable prestretch to the spring 31. ln ordinary lire doors there is no special device for fixing the desired pre-stretch, and the amount used is` usually determined by estimate.` If there isftoo much pre-stretch, there is aXial strain which kproduces an undue amount of friction. if there is not enough pre-stretch, then the coils rub on each other and the spring buckles and binds. furnishes a means for determining this so that workmen are never at a loss in getting the proper adjustment, and in shipping and erecting there is no possibility of displace,- ment. y

The barrel le and shaft 24; are shown of equal length, and it willbe convenientto make them that way. rlhen if the holes in the hubs 2O and 21 are of less depth than the inner faces of the covers 13 and 19, the shaft will position the barrel with` respectto the brackets 11 and 12. This will be evidentv from the fact that screw 26 is secured to the shaft and screw 25 is secured to4 the bai.k rel, and that the stretched spring 31 holds these screws into engagement with the spacer 33, vWith the square shaft here shown, the

YlChespaeing tube 33 only purpose of the screw 30 is to position 'l'.helshaft longitudinally with respect to the barrel so that contact between the ends of i the shaft and the covers 13 and 19 will position. the barrel with respect to the brackets.

lt is to be observed. that the shaft 24k is a square shaft, has no holes drilled in it, and

has to carry practically no load beyond itsr is teV fuinislr own weight. -1ts function winding tension for the spring 3l, theY axial tension being furnished by .the spacer 33. As the hole in the screw 26 is a square hole to match the shape of the shaft,the set screw Y 30 has nothing to do other than prevent accidental longitudinal. displacement. l

1in ordinary devices of this kind, the barrel lies between the brackets which cariyl it, aiid is mounted on a shaft which'has bearings in the brackets. rlihis shaft is necessarily of small diameter as compared to that of the barrel, and has to carry the entire load in ad@ dition to the torsional strain of winding the spring. it is to be observed that Irun the barrel itself thru thek brackets and have the load carryingbearings on the large barrel and not on a` small shaft.A This adds much i to the substantial nature of the structure.

lVhen the barrel itself hasits bearings in I the supporting brackets, it may lbe removed to *releasev the other end, and then lowering the released end and` drawing the other end .Y

inward. There are noA such conveniences in removing a barrel which is mounted upon a shaft which is itself carried in bearings-` rlhe roller bearings in the presentcase do something more than produce a bearing of small friction. Theymake it practicable toV use the entire diameter of the barrel in the bearings and thus provide a better load carrier, they provide accommodation for variations from accurate alignment without the production of undue friction, and they make it easier to erect the device and to take it down Y for repairs.

VVhatI claim is:

l. In a device of the class described, brackets at opposite sides of a doorway, a curtain-carrying barrel having bearings in said brackets, a spring for balancing the weight of the curtain, and a central shaft serving as a means for applying tension to .said spring, the weight of said parts being carried by the barrel resting on its bearings.

2. In a device of the class described, brackets at opposite sides of a doorway, a barrel having bearings in said brackets, ,a spring within the barrel, and a central shaft manually adjustable to apply tension to said spring and serving to position said barrel in its bearings.

3. In a device of the class described, brackets located at opposite sides of a doorway, a curtain-carrying barrel extending thru openings in said brackets, roller bearings located in said openings and serving to support the endsv of the barrel, and removable stops secured to the bearings adjacent to theends of the barrel and serving as means for determining the position longitudinally of the barrel in its bearings.

el. In a device of the class described, bearings located at opposite sides of a doorway, a curtain-carrying barrel extending thru said bearings and supported therein, a spring within the barrel for balancing the weight of a curtain carried thereby, and means for adjusting the tension of said spring.

In a device of the class described, brackets, a barrel having bearings in said brackets, covers on the outer faces of the brackets and provided with inwardly projecting hubs, a shaft extending thru the barrel and having its ends projecting into said hubs, and a spring having one end secured to the shaft and the other end secured to the barrel.

G. In a device of the classdescribed, brackets, a barrel having` bearings in the brackets, a square shaft extending thru the barrel, covers on the outer faces of the brackets and having parts engaging the ends of the shaft, one of said parts having a square hole to receive and' match the square shaft, and a spring having one end secured to the shaft and the other end secured to the barrel.l

f2'. In a device of the class described, brackets, a barrel having bearings in the brackets, a sqnareshaft extending thru the barrel, a spring within the barrel and around the shaft, devices mounted upon the shaft and connected to the ends of the spring, one of said devices having a square hole to fit the shaft and being clear of the barrel and the other of said devices being secured to the barrel 'and having a hole which clears the shaft, and means carried by one bracket for turning the shaft to give tension to the spring.

8. In a device of the classl described, the combination with a barrel and bearingsin which the barrel turns, of a centrally supported shaft within said barrel, stops connected to the bearings and engaging the ends of the shaft to hold it from axial movement, and an adjustable connection between shaft and barrel so that said stops may serve to hold said barrel at a desired axial position in its bearings. n

9. In a device of the class described, a barrel, a shaft therein, a screw connected to the barrel, a second screw connected to the shaft, and a spring mounted upon said screws and having its ends turned in to engage the threads of the screws.

10. In a device of the class described, a barrel, a square shaft extending therethru, a screw connected to the barrel and free from the shaft, a second screw having a square hole to fit the shaft, and a spring mounted upon said screws and havingfits ends inturncd to engage the threads of the screws.

Il. In a device of the class described, a barrel, a central shaft therein, a device conf nected to the barrel but free from the shaft, a second device connected to the shaft but free from the barrel, a spring having its ends connected to said devices respectively, and a spacing tube between said devices and arranged to give a pre-stretch to the spring.

l2. In a device of the class described, a helical spring, heads connected to the ends of the spring, and a spacing tube between said heads and serving to give a pre-stretch to said spring, said parts being so constructed that one head may be connected to a barrel and-the other head may be connected to a shaft.`

I3. In a device of the class described, horizontal shaft, a bracket having a vertical web thru which the shaft extends, and rollers confined between the shaft and the bracket so as to form a roller bearing for the shaft, the web of the bracket having a small opening over the center of the shaft thru which opening the rollers are inserted in the bearing.

14. In a device of the class described, brackets at opposite sides of a doorway, a curtain-carrying barrel having its ends Lextending thru openings in said'brackets, and

roller bearings carried in the openings in said brackets and supporting the ends of the barrel.

15. In a device of the class described, brackets at opposite sides of a doorway, a curtain-carrying barrel having its ends extending thru openings in said brackets, and

roller hearings for said barrel formed hy its ends, Withinsaid hearings, Said hearings duinbbell shaped rollers having their lheads being so constructed that the Vbarrel niay be engaging the harei and their necksl riding removed from the bearingsV at the place be- 19 on edges 01"' the openings in the brackets. tween them While said hearings remain in 16. In a device of the class described, fixed position.

bearings located on Opposite sides of a dool- Way, and a curtain-carrying barrel having SAMUEL P. SMURR. 

